Production of cuprous naphthenate in the treatment of petroleum oil



June 7, 1949; c. o. HOOVER PRODUCTION OF CUPROUS NAPHTHENATE IN THE TREATMENT-OF PETROLEUM OIL Original Filed Ooit. 2, 1946 2 Sheets-Sheet 1 2 Sheets-Sheet 2 June 7, 1949. C, Q HOOVER PRODUCTION 0F CUPROUS NAPHTHENATE IN THE TREATMENT 0F PETROLEUM OIL Original Filed Oct. 2, 1946 naphthenate or other cuprous soap, which, having a higher boiling point than that prevailing in the reaction chamber settles to the bottom and is withdrawn. The withdrawn cuprous soap, as such or after being subjected to oxidation to convert it to the cupric state is returned for treatment of further amounts of crude oil.

For a further and more complete understand-A ing of the invention, reference is made to the accompanying drawings in which:

Fig. 1 is a iiow sheet illustrating one method in which the process of the present invention may be carried out in a cyclic manner in connection with the treatment of crude petroleum oil with a copper soap, and

Fig. 2 is a iiow sheet of a slightly modified arrangement.

Referring first to Fig. 1, a charge of crude petroleum oil passing through a conduit I, together with a small amount of a copper soap, for example cupric naphthenate, introduced through a conduit 2, is pumped by a pump 3 through a charge heater i where the temperature of the crude petroleum oil is raised to its :dashing point, for example about 750 F. I'he thus heated crude oil, together with the copper naphthenate contained therein, is then introduced into the lower portion of a fractionation column 5, whereupon the petroleum oil flashes, forming a vapor phase consisting of distillates and naphthenic acid resulting from decomposition of the copper naphthenate, and a liquid phase consisting of fuel oil which carries the copper product of the decomposition of the copper naphthenate. The copper product and the fuel oil settle to the bottom of the column.

The vapor resulting from the flashing of the hot charge of crude oil in the fractionation column 5 may be fractionated into as many fractions as desired. As shown in Fig. 1, it is divided 1,

into a light gas and gasoline fraction which is withdrawn from the top of the fractionation column 5 through a conduit 6, a heavier fraction of light distillates which is withdrawn at a lower level from the column through a conduit 1', and a still heavier fraction consisting essentially of gas oil which is withdrawn from a still lower portion of the column, through a conduit 8. The fractions withdrawn through the conduits 6, 1, and 8 will contain varying amounts of the naphthenic acid resulting from the decomposition of the copper naphthenate, and, if the crude oil is of the naphthene-base type, from the presence of naphthenic acid present, as such, in the original crude oil. However, most of the naphthenic acid will be contained in the gas-oil fraction withdrawn through the conduit 8. The fractions withdrawn through the conduits 6, 1 and 8 may be passed through condensers 9, I0 and I I, in accordance with the usual practice.

In accordance with the present invention, any one or all of the fractions withdrawn through the conduits 6, 'I and 8 may be treated with a fluid suspension of a finely-divided copper compound such as those referred to above, provided, that if the copper compound is metallic copper, suicient oxygen must be introduced to convert the metallic copper to copper oxide.

As Shown in Fig. l, the oil fraction withdrawn through the conduit 8, which contains a relatively large percentage of naphthenic acid resulting from decomposition of the copper naphthenate used in the treatment of the oil is passed through a neutralizer I2 where it is caused to react with one or more of the copper compounds referred to above, or copper oxide resulting from the oxidation of finely divided metallic copper supplied in the form of an oil suspension or slurry. The copper compound is supplied from a hopper I3 to a mixing drum I4 where it is intimately mixed with an oil having a boiling point slightly higher than the temperature of the oil vapors passing into the neutralizer I2, so that when subjected to the temperature prevailing in the neutralizer I2 it will not be vapor- ,ized and pass from the neutralizer with the hot oil vapors. Ordinarily, an oil having a boiling point of 800 F. or higher is satisfactory, as the temperature in the neutralizer will not exceed about 750 F.

In order to obtain intimate mixing and suspension of the copper compound with the oil in the mixing drum I4, a portion of the oil and copper compound may constantly be withdrawn from the bottom of the mixing drum and circulated back to the top thereof through a conduit I6 by means of a suitable circulating pump I1.

The suspension or slurry of finely-divided copper compound in the oil is withdrawn from the mixing drum Ill by a pump I8 and passed through a conduit I9 and yintroduced therefrom into an upper portion of the neutralizer I2. The neutralizer I2 is maintained substantially filled with baflles, chains or some other inert material which will cause a large surface contact between the oil-copper-compound slurry and the hot oil vapors containing the naphthenic acid. As the hot gas oil vapors and the naphthenic acid rise in the neutralizer I2 countercurrent to the downwardly flowing oil-copper-compound slurry or suspension the naphthenic acid contained in them comes into intimate contact with the nelydivided copper compound of the oil-copper-compound slurry, with resulting formation of copper naphthenate. The copper naphthenate immediately dissolves in the carrier oil slurry and is temporarily retained in the neutralizer I2 due to the fact that it has a higher boiling point than the gas oil vapors passing through the neutralizer. The pressure in the neutralizer I2 is not important; it may be that prevailing in columns where gas oil vapors are fractionated.

In order to obtain complete reaction between the copper compound of the oil-copper-compound slurry and the naphthenic acid contained in the hot gas-oil vapors, the oil-copper-compound slurry containing dissolved copper naphthenate formed by reaction of the copper compound with naphthenic acid constantly is withdrawn from the bottom of the neutralizer I2 through a conduit 20 and is pumped by means of a pump 2| through a conduit 22 back to the upper portion of the neutralizer. The conduit 22 is provided with a valve 23 which normally is so adjusted that a relatively small proportion of the oil containing the copper naphthenate in solution constantly is withdrawn through a conduit 24. The gas oil freed of the naphthenic acid, but containing vapors of any vaporizable substance formed as a result of the reaction between the copper compound and the naphthenic acid in the neutralizer I2 is withdrawn from the top of the neutralizer through a conduit 25 leading to the condenser II. The steam or any other vaporized products of the reaction between the copper compound and the naphthenic acid may be separated from the hot oil vapors in the condenser II, or otherwise by means well known in the industry.

The cupric naphthenate dissolved in the oil ali-'facce 'withdrawn'through the conduit 24 is cycled back thenic acid, the amount of cuprous naphthenate `formed in the neutralizer I2 may be more than is Lnecessary for re-use in the system. In such case,

any such excess of cuprous naphthenate may be -withdrawn through a bleed conduit 26 controlled `by a valve 2'I; or the excess naphthenic acid may bei permitted to remain in the distillate, reacting only sufiicient of the naphthenic acid with the copper compound to form the required amount of cuprous naphthenate for subsequent Are-use in the treatment of further amounts of crude oil. That may be done by restricting the amount of copper compound in the oil-copper slurry vavailable for reaction with the naphthenic acid in the neu-tralizer I2, or by by-passing a portion of the `hot gas oil vapors through a conduit 8a controlled by a'valve 8b. On the other hand, should the amount of naphthenic acid contained in the crude petroleum be insufficient to compensate for that lost by removal with lighter fractions not treated for the recovery of the naphthenic acid content thereof, such additional amount of naphlthenic acid as maybe necessary to produce sui- 'cient cuprous naphthenate for xing the sulfur compounds in the crude oil may be introduced through a conduit 2B.

`The copper product and the fuel oil may be "withdrawn from the bottom of the fractionation column 5 through a conduit 29 and passed to a VAsuitable thickener or lter 30 where the copper 4'product is separated from the fuel oil. The fuel "oil may be withdrawn through a conduit 3| while 'the copper product is withdrawn through a conduit 32 and suitably treated for regeneration to lthe ycopper compound to be introduced into the oil suspension to the neutralizer I2 to react with the naphthenic acid therein. For example, the

copper product may be passed into an oxidizer v33v where it is converted to the oxide, and the resulting oxide passed through a conduit 34 to thehopper I3. If it is desired to use a copper compound other than the oxide for reaction with the naphthenic acid in the neutralizer I2, the

copper product passing from the thickener or ilter" 30 may be treated in any other conventional manner to convert it to the desired compound.

-In case it should be desired to treat the crude 4oil with cupric naphthenate instead of cuprous 'naphthenate for the purpose of Xing the Sulfur "compounds contained therein, the oil solution of cuprous naphthenate being recycled may be bypassed through an oxidizer 35 suitable pipes and valve connections being provided for the purpose.

Oxygen or an oxygen-carrying gas may be intro- `duced through a pipe 36 for passing through the oil solution of cuprous naphthenate in the oxi- `diner 35 for the oxidation of the cuprous naphthenate to cupric naphthenate.

In Fig. 1 only the gas-oil fraction withdrawn from the lovvervportion of the fractionation co1- umn 5 is treated for recovery of the naphthenic acid and its conversion to cuprous naphthenate.

However, if desired, the fractions withdrawn `through the conduits 5 and 'I also could be passed .throughneutralizers similar to the neutralizer I2 for the conversion of the naphthenic acid content thereof to'cuprous naphthenate,such'neutralizers being indicatedin dotted lines at I 2c` and' 'I2b, respectively.

If the oil-copper-compound suspension for slurry contains finely-divided metallic copper,'"it is desirable that air or other suitablesupplyfof gaseous oxygen=beintroduced into the neutralizer I2 so that the metallic copper carried in the suspension of slurry rst'may be oxidized'toicopper oxide inwhich form the copper is more reactive with the naphthenic acid contained in lthe'gasoil vapors. Air for' that purpose may be introduced into thel neutralizer I2 through a conduit 31.

If the invention is carried out as just described, that is, by the introduction of metallic copper into theneutralizer I2 and its subsequent 'oxidation to copper oxide by air or other oxygen-carrying gas supplied through the conduit 31,' the copper naphthenate formed by reaction between the copper oxide and naphthenic acid contained in the gas oil vapors will be in the cuprous state, as cuprous naphthenate exists at the tempera ture prevailing in the neutralizer I2, even should there be an excess of oxygen present.

In Fig. 2, there is disclosed a modified form of the invention which is similar to that disclosed in Fig. l in all respects except that the copper compound instead of being suspended in a highboiling oil and introduced into the neutralizer I2' in the form of an oil-copper-compound slurry, is suspended in a gas and introduced in a gaseous stream into a lower portion of the neutralizer I2. Referring' to that figure, the copper compound, which like the copper compoundreferred tov in connection with the previous form of the invention, may be cupric oxide, cuprous oxide, cupric hydroxide, cuprous hydroxide, cupric carbonate, cupric acetate or finely-divided metallic copper or other compounds thereof, is introduced from a hopper 38 into an eductor 39 where it is picked up and suspended in a suitable gaseous medium introduced through a conduit 40. If the copper compound is finely-divided metallic'copper, the gas passing through the conduit 40 for suspending the finely-divided copper should contain a sufficient amount of oxygen to oxidizethe metallic copper to copper oxide before it reacts with the naphthenic acid contained in the gas oil vapors, as described above. In order to avoid possible oxidation of hydrocarbon vapors, I prefer that the amount of oxygen so introduced into the neutralizer not be in excess of that needed for oxidation of the metallic copper to copper oxide. Ifk the copper supplied from the hopper 38 is in the form of a copperk compound, such as those referred to above, the nature of the gas passing through the conduit 40 for suspension of the finely-divided compound is immaterial, as long as it is inert with respect to the gas oil vapors and naphthenic acid passing through the neutralizer I2. It may be air, any inert gas, or still gas; or it maybe a portion of the gas oil vapors by-passed from 'the charge beater 4.

The finely-divided copper compound suspended in the gaseous medium in the eductor 39 is passed through the conduit 40 into the lower portion of `the neutralizer I2 and passes therethrough concurrently with the hot gas oil vapors containing the naphthenic acid introduced throughthe conduit 8. As the hot oil vapors containing 'the naphthenic acid and the gaseous or vaporous suspension of the finely-'divided copperl compound passes upwardly through the neutralizertl21the copper compound reacts with thenaphthenicacid contained in the hot oil vapors with resultant formation of cuprous naphthenate, which being a liquid having a boiling point higher than the temperature prevailing in the neutralizer I2 settles t the bottom of the neutralizer and may be withdrawn through the conduit 4l and recycled back to the conduit 2 for use in the fixation of sulfur compounds in further amounts of crude oil. In all other respects the process represented by the ow sheet of Fig. 2 is identical with that described above in connection with the flow sheet of Fig. l, and like reference characters, primed, have been used to designate like parts of the apparatus.

From the foregoing it will be apparent that the present invention provides a process for converting naphthenic acid to cuprous naphthenate, and to a process which particularly is adapted to form a part of a cyclic process for the treatment of crude petroleum oil with cuprous or cupric naphthenate, in which naphthenic acid liberated as a result of the treatment oi the oil with the cuprous or cupric naphthenate is recovered and used in the reformation of cuprous naphthenate, which, if desired, may be oxidized to cupric naphthenate for the treatment of further amounts of crude oil. When used in connection with a process for fixing sulfur compounds obtained in crude petroleum oil it has the further advantage of improving the quality of the distillates which are recovered due to the fact that the naphthenic acid and other organic acids which are present in the distillates are removed.

While the invention has been particularly described in connection with the production of cuprous naphthenate from naphthenic acid, it is to be understood that the process is equally applicable for the production of other cuprous compounds of Water-insoluble organic acids such as cuprous compounds of oleic, stearic, tall-oil, linoleic, and resin acids. Thus, if cuprous or cupric talla-te, for example, were used for the xation of sulfur compounds in the crude petroleum oil, tall-oil acid would result from the decomposition of the cuprous or cupric tallate in the fractionation column which could be reacted with the finely-divided copper compound to form cuprous tallate, which subsequently could be used as such, or oxidized to cupric tallate, in the manner described above for the treatment of further amounts of crude oil.

While the charging stock introduced through the conduit i h'as been referred to as crude petroleum oil, it is to be understood that it might be any other stock which it is desired to treat with a copper naphthenate for the fixation of sulfur compounds contained therein.

It also will be understood that while the petroleum vapors containing the Water-insoluble organic acid are brought into intimate contact with the copper compound after at least partial fractionation of the vapors, if desired, the heated stock containing the copper soap iirst could be introduced into a flash drum, and all of the vapors therefrom and the water-insoluble organic acid carried 'thereby brought into intimate contact with the copper compound and the oil vapors, stripped of the acid vapors, thereafter fractionated, as described in my co-pending applicationJ Serial No. 700,823 iiled October 2, 1946.

Various changes may be made in the procedure without departing from the invention or sacriiicing any of the advantages thereof.

I claim:

1. In the process of treating petroleum oil with a copper soap of a water-insoluble organic acid for the iixation of sulfur compounds contained therein in which the copper soap is introduced into the oil and the oil subsequently is subjected to heat treatment with the liberation of vapors containing the organic acid resulting from decomposition of the copper soap; the improvement which comprises passing the liberated vapors containing the organic acid into intimate contact with a finely-divided copper compound suspended in a fluid medium which is inert with respect to the oil vapors and the organic acid, with resultant formation of the cuprous soap of the acid, and using the thus formed cuprous soap as the source material of the copper soap used in the treatment of further 4amounts of oil.

2. In the process of treating petroleum oil with a copper soap of a Water-insoluble Organic acid for ie xation of sulfur compounds contained therein in which the copper soap is introduced into the oil and the oil subsequently is subjected to heat treatment with the liberation of vapors containing the organic acid resulting from decomposition of the copper soap, the improvement which comprises passing the liberated vapors containing the organic acid into intimate contact with a iineiy-divided copper compound suspended in a high-boiling oil which is inert with respect to the cil vapors and the organic acid, with resultant formation of the cuprous soap of the acid, and using the thus 4formed cuprous soap as the source material cf the copper soap used in the treatment of further amounts of oil.

3. In the process of treating petroleum oil with a copper soap of -a water-insoluble organic acid for the fixation of sulfur compounds contained therein in which the copper soap is introduced into the oil and the oil subseqently is subjected to heat treatment with the liberation of vapors containing the organic acid resulting from decomposition cf the copper soap; the improvement which comprises passing the liberated vapors containing the organic acid into intimate contact with a finely-divided copper compound suspended in a gaseous medium which is inert with respect to the oil vapors and the organic acid, with resultant formation of the cuprous soap of the acid, and using the thus formed cuprous soap as the source material of the copper soap used in the treatment of further amounts 0f oil.

4. In the process of treating petroleum oil with a copper soap of a water-insoluble organic acid for the 'Fixation of sulfur compounds contained therein in which the copper soap is introduced into the oil and the oil subsequently is subjected to heat treatment with the liberation of vapors containing the organic acid resulting from decomposition of the copper soap; the improvement which comprises passing the liberated vapors containing the organic acid into intimate contact with a finely-divided copper compound suspended in a uid medium which is inert with respect to the yoil vapors and the organic acid, at a temperature above about 225 C., with resultant formation of the cuprous soap of the acid, and using the thus formed cuprous soap as the source material of the copper' soap used in the treatment of further amounts of oil.

5. In the process of treating petroleum oil with a copper soap of a water-insoluble organic acid for the iixation of sulfur compounds contained therein in which the copper soap is introduced into the oil and the oil subsequently is subjected to heat treatment with the liberation of vapors containing the organic Iacid resulting from de- .amazes i icomposition:` of fthe copperrsoa1-ithe improvement v 'whichzcomprisesipassi-nglthe liberatedvapors conithe organic :acid'invaporousifformiinto .riintimate contact with. a;:iine1y-divided `copper ii-compound suspendedrir-i aiuidmedium which is :iinertilwithrespectto the oil vapors andthe organic .i .acid-,i yWithzresultantf-formation; of the .cuprous Y soap of the .acid-f, and `.using the rthus formed cucprousvsoapwas the source r material l' of Lthe v`copper f=soap=usedin the treatment of furtherramountsot 10 1 dwln the process .of treating petroleum oil Iwith i .fax copper naphthenate for the -Xationfof-fsulfur f compounds contained therein in -fwhichithe copper nz'naphtheniate is introduced :intolvthe oil and the...

'fi-oil; :subsequently isi-subjected, to fheat treatment oiandothe: liberation o .f vapors containing naph- 'i "thenicaacid resulting` from thedeconripositionv of :the :copper fnaphthenate 1 the improvement Iwhich comprises passing liberated vapors containing the;

i znaphthenic `acid into intimate s contact with a timely-divided V:copper compound y suspended a ".1 flui'd-- medium which is inert with `respect to the riroil vaporsA andthe naphthenic acid, with resultant rormationfof cuprousnaphthenate, and using thel :cuprous :naphtlfienatei` thus` formedv as the source zlmaterialwof .the copper naphthenateused in the i treat-ment offurther amounts of foil.

In the'p-rocess, of treating petroleum oil with acopperrnaphthenate for' thev xation of sulfur compounds contained :therein in whichethe "cop- Saper '.naphthenate isvintroduo'ed intol the oil: and rtheioilf subsequently is Asubjected toheat treat- .'-iment andi thefliberationfof vapors containing .n.aphthenicacidresulting from the decomposition a of the Vcopper naphthenatej the improvement "fwlii'chicomprises passing liberated -vaporscon- "taining the naphthenicfacidfinto intimate contact with a 'nely-divided copper compound sus- -fperidedy in a high-'boiling oil 'Which is inert With- 4 respect to the oil vapors and the naphthenic acid, with resultant formation of Icuprous naphthenate, and using the cuprous naphthenate thus formed as the source material'of the copper naphthenate .suseda in. ,fthe treatment oni :further amounts? of voil. f

Soilv subsequentlyA is .subjected-.to heat treatment '-5 :and thexliberationV of vapors containing naphfsthenic acid resulting. from. .theedecomposition of :the copperv naphthenate the :improvement AWhich @comprises passing. liberated'vzvapors containing the naphthenic acid into intimate contact with a finely-divided copper compound suspended in a gaseous medium which is inert with respect to the oil vapors and naphthenic acid contained in them with resultant formation of cuprous naphthenate, and using the cuprous naphthenate thus formed as the source material of the copper naphthenate used in the treatment of further amounts of oil.

9. In the process of treating petroleum oil with a copper naphthenate for the fixation of sulfur compounds contained therein in Which the cop-per naphthenate is introduced into the oil and the oil subsequently is subjected to heat treatment and the liberation of vapors containing naphthenic acid resulting from the decomposition of the copper naphthen-ate; the improvement which comprises passing liberated vapors containing the naphthenic acid into intimate contact with a finely-divided copper compound suspended in a uid medium which is inert with respect to the '10 i: oil vaporsl-andthefnaphthenio acid, at a temperaiture above about"225'C;, with resultantformafftionof cuprouswnaphthenate, and using the cuprous naphthenate-thusformed as the source material' of .the-copperfnaphthenate used in the treatment of -further amounts' of oil.

' 10..eIn'the process of treating petroleum voil with f, af copperlsoap'of aiwater-insoluble organic acid :for the' viixatio-isiof sulfur compounds contained v:thereininrwhich a-copper soap'is introduced into nthe yoil andthe oil subsequently is subjected to :heat treatment withitheliberation of vapors conitainingi :the Watereinsoluble organic acid resultitromdecompositionfof .the copper soap and a copper product; the improvement which .comr prises passing i theiliberated vvapors :containing the water-insoluble` organic` acid into intimate con- .:Ltact :with `a:iiiisielv-divided copper i compound with yfresultant.'iormation oif'thezcuprous soap of the 2dffacidiusingcthe :cuproussoap thus .formed as the sources material ofnthe-copper `soap used in the xtreatmentf ofxfurther: amounts 'or petroleum oil, J yand-1converting the/copper product to the desired y coppenrcompoundnfor reaction with further ramounts;ofnwater-insoluble organic acid. conl:tained ilwapors.

i 11.. .Inlth'el process of treating petroleum o-il with l -awcopper lsoap4 of va1 .Water-insoliible organic acid v4ff-or the fixation r" oiffsul--run compounds contained therein in which a" copper soap introduced into :theoilvandfzthezfoil subsequentlyA is Asubjected to .':heat'treatmentvwithitherliberation of vapors conf: taining; the watereinsoluble: organic .acid resulting from decomposition of the copper soap and H va copperip'roductftheimprovement which com- ;f prises passing" theliberatedlvapors containing'the 'Water-insoluble organic acid-into-intimate conctact Witha finely-divided copper compound, at a -temperaturefabovei,about225 C., with resultant o `formation of, the cuproussoap oi.l the acid, using f the .'cuprous soaptthusiormedfas the source maflterial: oftthe copper .soap vused in the treatment -'of..further .amounts of petroleum yoil, .and converting then-copper product. tothe .desired copper com- 'pound for-reaction with further amounts of Water-:insoluble organiciacid contained in oil vapors. 'x11/,Iny the process of treating petroleumoil with a copper :soapf of afwater-insoluble vorganic acid for' thexationt. of sulfurfcompounds contained =:.therein in :which .a coppersoap is introduced into ltheffoils-azrid:the`oil1-subseo1uently is subjected to heat .treatment with. the liberation voffvapors containing the water-insolubleorganic acid resulting fromfdecomposition ofthe copper soap and a copper product; the improvement which comprises passing the liberated vapors containing the Water-insoluble organic acid into intimate contact with a iinely-divided copper compound suspended in a high-boiling oil which is inert with respect to the oil vapors and the water-insoluble organic acid, With resultant formation of the cuprous soap of the acid, using the cuprous soap thus formed as the source material of the copper soap used in the treatment of further amounts of petroleum oil, and converting the copper product to the desired .copper compound for reaction With further amounts of water-insoluble organic acid contained in oil vapors.

13. In the process of treating petroleum oil with a copper soap of a Water-insoluble organic acid for the xation of sulfur compounds contained therein in which a copper soap is introduced into the oil and the oil subsequently is subjected to heat treatment with the liberation of vapors containing the Water-insoluble organic acid resulting ltarrarss from decomposition of the copper soap and a copper product; the improvement which comprises passing the liberated vapors containing the water-insoluble organic acid into intimate contact with a finely-divided copper compound suspended in a gaseous medium which is inert with respect to the oil vapors and the water-insoluble organic acid, With resultant formation of the cuprous soap of the acid, using the cuprous soap thus formed as the source material of the copper soap used in the treatment of further amounts of petroleum oil, and converting the copper product to the desired copper compound for reaction with further amounts of water-insoluble organic acid contained in oil vapors.

14. In the process of treating petroleum oil with a copper naphthenate for the iixation of sulfur compounds contained therein in which a copper naphthenate is introduced into the oil and the oil subsequently is subjected to heat treatment with the liberation of v-apors containing naphthenic acid resulting from the decomposition of the copper naphthenate and a copper product; the improvement which comprises passing liberated vapors containing the naphthenic acid into intimate contact with a nely-divided copper compound, with resultant formation of cuprous naphthenate, using the thus formed cuprous naphthenate as a source material of the copper naphthenate used in the treatment of further amounts of petroletun oil, and converting the copper product to the desired copper compound for reaction with further amounts of naphthenic acid.

15. In the process of treating petroleum oil with a copper naphthenate for the xation of sulfur compounds contained therein in which a copper naphthenate is introduced into the oil and the oil subsequently is subjected to heat treatment with the liberation of vapors containing naphthenic acid resulting from the decomposition of the copper naphthenate and a copper product; the improvement which comprises passing liberated vapors containing the naphthenic acid into intimate contact with a finely-divided copperl compound, at a temperature above about 225 C., with resultant formation of cuprous naphthenate, using the thus formed cuprous naphthenate as a source material of the copper naphthenate used in the treatment of further amounts of petroleum oil, and converting the copper product to the desired copper compound for reaction with further amounts of naphthenic acid.

16. In the process of treating petroleum oil with a copper naphthenate for the iixation of sulfur compounds contained therein in which a copper naphthenate is introduced into the oil and the oil subsequently is subjected to heat treatment with the liberation of vapors containing naphthenic acid resulting from the decomposition of the copper naphthenate and a copper product; the improvement which comprises passing liberated vapors containing the naphthenic acid into intimate contact with a finely-divided copper compound suspended in a high-boiling oil which is inert with respect to the oil vapors and the naphthenic acid, with resultant formation of cuprous naphthenate, using the thus formed cuprous naphthenate as a source material of the copper naphthenate used in the treatment of further amounts of petroleum oil, and converting the copper product to the desired copper compound for reaction with further amounts of naphthenic acid.

17. In the process of treating petroleum oil with a copper naphthenate for the fixation of sulfur compounds contained therein in which a copper naphthenate is introduced into the oil and the oil subsequently is subjected to heat treatment with the liberation of vapors containing naphthenic acid resulting from the decomposition of the copper naphthenate and a copper product; the improvement which comprises passing liberated vapors containing the naphthenic acid into intimate contact with a finely-divided copper compound suspended in a gaseous medium which is inert with respect to the oil vapors and the naphthenic acid, With resultant formation of cuprous naphthenate, using the thus cformed cuprous naphthenate as a source material of the copper naphthenate used in the treatment of further amounts of petroleum'oil, and converting the copper product to the desired copper compound for reaction with Vfurther amounts of naphthenic acid.

CHARLES O. HOOVER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,071,862 Fisher Feb. 23, 1937 2,091,239 Hall Aug. 24, 1937 2,157,767 Long May 9, 1939 2,273,263 Happel et a1 Feb. 17, 1942 2,395,307 Weber et a1 Feb. 19, 1946 

